Abstract Detail

Early Cenozoic woods from South China and their phytogeographic and paleoclimatic implications.

Although fossil woods are abundant in China, previously described taxa are mainly from Yunnan, Hubei, East and North China with rare fossil woods collected from South China. In this report, we introduce Early Cenozoic woods collected from Hainan Island and Guangdong, South China. The Hainan woods are collected from Changchang Basin (Late Eocene), Jialai-Nanbao Basin (Early-Middle Miocene) and Ledong (Oligocene-Miocene). The Hainan woods include Altingioxylon hainanensis (Altingiaceae), Paraphyllanthoxylonhainanensis (Euphorbiaceae), Pahudioxylon nanbaoensis & Pahudioxylon bankurensis (Leguminosae), Mesuoxylon sp. (Guttiferae), Araucarioxylon sp. 1 & 2 (Araucariaceae). The Guangdong woods are collected from Maoming Basin (Late Eocene) including Bischofiamaomingensis (Phyllanthaceae) and Myrtineoxylon maomingensis (Myrtaceae). Based on taxonomic identification, we discuss the phytogeographic history of some fossil wood taxa. Altingioxylon hainanensis is the first fossil wood record of Altingiaceae found in China and the most ancient wood evidence for this family in eastern Asia; Paraphyllanthoxylonhainanensis and Pahudioxylon nanbaoensis are the first records of these two genera in China; Bischofia maomingensis is the earliest Bischofia woods in China; Myrtineoxylonmaomingensis is not only the first wood fossil but also one of the earliest plant megafossils of the tribe Myrteae in eastern Asia. The nearest living relatives of these woods are mainly tropically, sub-tropically distributed taxa, indicating that the early Late Eocene climate of South China is likely to be warm and moist. The palynological assemblage of the Maoming Basin indicates that paleoclimate became cool and seasonality increased from the late Late Eocene. The distinct growth ring in Pahudioxylon nanbaoensis shows that this seasonal climate probably persisted till the Early Miocene.